Tectonoelins, new norlignans from a bioactive extract of Tectona grandis

► Teak wood is an excellent source of natural bioactive compounds. ► The structure elucidation of new norlignans, tectonoelin A and B, is reported. ► This is the first isolation of C8-C8′ linkage norlignans from a dicot. ► The bioactivities of the isolated compounds have been studied. ► The isolated lignans and norlignans should be part of the defence mechanisms.